Press for copying letters



UNITED STATES PATENT GFFICE.

GEO. BURNHAM, OF PHILADELPHIA, PENNSYLVANIA..

PRESS FOR COPYING LETTERS.

Specification of Letters Patent No. 7,696, dated October 8, 1850.

To all whom it may concern Be it known that I, GEORGE BURNHAM, of the city of Philadelphia, in the State of Pennsylvania, have made certain new and useful Improvements in the Manner of Constructing a Press fo-r the Copying of Letters; and I do hereby declare that the following is a full and eXact description thereof.

My press is of the pla-ten kind, the letter from which the copy is to be taken, and the book or paper which is to receive the impression being placed between two metallic plates, which are to be drawn together when the impression is to be taken; but I have so arranged and combined the pressing plates and the other parts of the apparatus as to render the press much more pleasant in its action than those generally used and much less-liable to the failure of its parts.

In t-he accompanying drawing Figure l, is a vertical section of the press from end to 'end near its middle and Fig. 2, an end view thereof.

A, A, is the upper plate or table of the press, and B B the lower plate between which the copying is to be effected. The lower plate rests on a strong steel spring C C, a top and edge view of which are shown in Fig. 3. The plate B, is curved on its under side and the spring C, may also be curved to any desired extent, so that its elastic action shall continue during the whole time of taking the impression. E, E, are two levers which when the press is out of use stand in the position represented in Fig. l, in which position the plates are also ready to receive the letter and copying paper between them. By drawing these levers E, E, apart the plates A, and B, will be made to approach each other, and a copy may be taken. D, D, are bolts which pass through the plate A, and the ends of the steel springs C, C, where they are furnished with adjusting nuts P, P.

The levers E, E, work, on joint pins a, the circular ends of these levers being received within brackets F, F, on the upper side of the plate A. In their eccentric action these levers operate in the same way with the single lever now in common use in the platen copying press, but those used by me work with a degree of ease and smoothness of which said press is not susceptible and furnish a perfect impression with apparently much less force, arising from the elasticity of the spring, and the more ad vantageous manner in which the power is applied to the levers.

Having thus fully described the nature of my improvement in the manner of con structing my platen press for the copying of letters, what I claim therein as new, and desire to secure by Letters Patent is,`

The manner in which I have arranged. and combined the two plates, or platens A, and B, with the two levers E, E, and with the steel springs C, C as set forth; the two plates being made to approach each other by the drawing apart of the levers E, E. The two bolts D, D, that are operated on by said levers, passing through the outer ends of the spring C, which is curved, and operates on the curved bottom of the plate B, in the manner and for the purpose set forth.

GEO. BURNHAM.

Vitnesses:

J. WV. McMAHoN, WV. R. SMITH. 

